It is known that with reference to any type of analogue or digital receiver, the quality of the uplink is considerably limited by the presence of interference which can disturb the signal processing on the receiving chain.
The presence of a strong input signal can in fact activate the ALC (Automatic Level Control) circuit, which is responsible for automatically adjusting the signal power in order to maintain it constant even in the event of fast variations in the input signal.
This can inevitably lead to an indiscriminate reduction of the disturbed input signal or, with reference to a digital receiver, it may cause the saturation of the ADC (Analog to Digital Converter) circuit, with the consequent incorrect digitalisation of the signal.
Therefore, it is of fundamental importance to be able to efficiently cancel the interference on the uplink signal.
In particular, the filters used must necessarily have an extremely selective frequency response, in order to ensure the elimination exclusively of the part of interference relating to the uplink signal.